Process of brazing metals.



' L. L. WHITE. ,'PROGESS OEBEAZING METALS.

APPLICATION FILED JUNE 16I 1905,

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PATENTBD JULY 31, 1906.v

UNITED STATES ,PATENT OEEIOE.

LOUIS L. WHITE, or roRTLAND. OREGON, ASSIGOR TO ,CHARLES E. LADD,

OE PORTLAND, OREGON.

PROCESS oF BnAzlNe-METALS. i

To all whom ifm/wy concern: y

"Be it known `that I, LOUIS L. WI-IITE,`a citizen of the United States, residing inthe city `ing of pieces of cast-iron.

of Portland, in the county of Multnomah and Stateof Oregon, have invented anew andk fected by the use of a commercial article generally known as spelter a flux of borax' being first used, by the'chemical action of whichv the pieces to be united are prepared for the application of spelter. j Both the spelter` and the iux are heated to a liquid form before being used. One of the chief difficulties heretofore experienced in the use of spelter for brazing has been the lack of a method of controlling the spelter within the two pieces of metal to be joined sufficiently long to enable a union to take place. j By my prrxiess, hereinafter described, I am able to control the spelter 'for any necessary length of time, and thus overcome this diliculty, as hereinafter indicated.

Mybrazing process .is carried on substantially as follows: lThe pieces of metal to be joined are temporarily joined together by suitable holdin devices, an appreciable space beingleft'` etween the two surfaces to be oined, and by my process this space, however lar e, may be filled with spelter and a unione ected; but inordinary use a very slight space only between the two pieces to be joined is left. The temporary clamping of the two pieces maybe done by any suitable device which will enable the desired work to be accomplished, such as by rivets, braces, binding vby wire, or other temporary device. I next ring the joint with a ring of soft wax rolled around the joint, pressing the sameclosely to the metal so as to exclude from the space between thetwo pieces to be joined any of the investment material herej mafter referred to. vThe purpose of this wax ring is also to provide a chamber around the joint and inside the investment when the Wax has been melted away by the further process indicated below. This ring, however, can

Specification of Letters lPatent.

Application ned Jun. 16.1905. sain No. 265,662.

Patented J'u1y 31, 1906.

be formed of any other material that may be burned or otherwise disposed of by heat; but

in 1practical experience the soft wax is preferab e. The chamber thus formed, which is first filled' with borax and subsequently with spelter, as indicatedv below, enables me to control the spelter sufficiently long to eHect union. Access to the chamber isnecessary to enable the borax and spelter to be vap lied, and I provide therefor .an entrance and) channel thereto through the investment material, which can 'be accomplished by small necks of wax connected with the wax ring and extending above the surface of the investment material, though sometimes, deterbestos thoroughly mixed,-so as to produce a paste, of about the consistency of` breaddough. Any other investment material, however, which will resist the action of heat, may be used. I envelop or acket the proposed joint, covered with its ring of wax, as above indicated, with this investment material, and if the parts to be brazed are small the best results from this investment are secured by binding it around the joint with a strip of cloth tightly drawn to make perfect contact between the jointA and the investment material. I then subject the work to a moderate degree. of heatfor the purpose of driving off the moisturefrom the investment material, and the moisture having Abeen eva orated the joint is left incased in a hard she l, which will resist the action of heat up to that -degree which is necessary in the subsequent process without any resultant cracking or warping of the investment. The heat by which I drive out the moisture also meltsthe exit Y 'mined by the character of the work, but one wax ring inside, the melted wax being either absorbed by the investment material or passing out from the chamber through the entrance and exit orifices thereto, thus leaving thezjoint encircled with a chamber inside the investmentfor receiving the borax and spelter in thesubsequent process. The work is now ready for the furnace, no particular construction of whi eh is necessary. Any fire whichwill heat the joint to be'brazed to the proper degree 'of heatiwill answer the purpose. The work IIO may be laced in an ordinary blacksmith forge, wit i coke or charcoal around the same 1n sufficient quantity to get the desired heat, or a gas or gasolene furnace may be used. I subject the joint to be brazed to a proper degree of heat, dependent somewhat upon the character of the metal to be brazed, but, generally speaking, to a bright cherry -red. Practical experience will guide the determination of the degree. When this proper degree of heat has been reached, the chamber around the joint is filled with liquid borax which has been melted for that purpose and which is poured through the orifice or inlet which has been prepared therefor. The boraX completely fills the chamber inside the investment and finds its way in between the two pieces of metal to be brazed, and its action .chemically prepares the metal for the reception of the` spelter. Any other preparartion which will act upon the surfaces of the l joint in a similar way and chemically pre are {thein for the spelter may be substitute for the boraXL The chamber being thus filled with borax, I immediately apply the substance commonly known in the commercial world as spelter and which in the meantime has been heated for this purpose, pro; ducing a liquid which will flow freely, the same being poured into the chamber already filled with liquid borax. The specific gravity of the spelter being heavier than that of the boraX drives out the latter through the exit-orifice provided, or where a single o ening to the chamber has been provide by way of entrance thereto this inlet may under some circumstances constitute the outlet. The chamber is thus gradually and completely filled with spelter, which has found its way in and around the joint, .filling the chamber completely and also filling the space between the particles to be brazed and perfectly excluding the air from the joint and also from contact with the spelter itself eX- cept at the orifice. The work is now allowed to cool, the investment material holding the liquid s elter in place until the joint solidifies an the union is effected. When the work is cool, the investment material is broken away and the joint finished with a file or emery.

In the accompanying drawings, forming a A part of this specification, I illustrate a joint -in the different steps or stages involved in the practice of my process. Thus Figure 1 shows in broken lines the joint, the covering of wax, and the means employed for holding the parts together reparatory to the process vof brazing, and in ll lines the air-excluding jacket. Fi s. 2 and 3 are sections on the lines 2 2 an 3 3 of Fig. 1.y Fig. 4 shows the joint after brazing, but before the surplus spelter has been removed.

In the drawings, 5 and 6 represent the parts of a shaft or axle which has been broken at the line 7. 'lhe parts are secured together in any suitable way-as. for instance, y the screw 8, passed diagonally through the abutting ends. Around the break the covering 9, of wax or other fusible material, is first applied, and then an exterior jacket 10 of fireresisting material is placed around the joint and outside of the wax, a sprue or opening l1 extending from the wax to the outside of the jacket, which may serve as an outlet for the melted wax and inlet for the borax and spelter. The joint repared as shown at Fig. 1 is next insertedp in a furnace or otherwise heated to fuse and drive out the wax, thereby forming a chamber within the jacket and around the joint. At the same time moisture in the jacket, if any, is driven off. As soon as the wax has been evaporated the parts will be in the condition shown in Figs. 2 and 3, with the exception that there will be an empty chamber around the joint in place of the wax. The borax is oured in at the sprue 11, filling the wax-c amber and the joint, and is followed by the s elter. Such of the spelter as does not enter t e joint forms a ring l2 on the outside of the joint. This ring is chipped off or otherwise removed as the final step of the process. i

Having thus described the process, I claim- 1. The improvement in the art of brazing metals, consisting in enveloping the joint with an air-excluding jacket of fire-clay and asbestos, or the like, and a plying first borax and then spelter to the jac eted oint.

2. The improvement in the art of brazing metals, consisting in enveloping the joint with an air-excluding jacket of fire-resistin material having an internal chamber aroun the joint, pouring liquid borax into said chamber and then following the borax with liquid spelter, the chamber controlling the spelter while the latter is cooling.

3. The improvement in the process of brazing consisting in providing the joint with an air-excluding jacket of fire-resisting material within which is an open chamber surrounding the joint, and applying first a preparation for chemically preparing the surfaces of the joint to unite with the spelter and then spelter to the jacketed joint.

4. The improvement in the process of brazing consisting in providing the joint with an air-excluding jacket of fire-resisting material Within which is an open chamber surrounding the joint, then heating the joint, and their filling the joint and chamber first with a preparation for chemically preparing the su races for the spelter and then with melted spelter.

LOUIS L. WHITE.

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